


In the Reptile House

by atamascolily



Category: Good Omens (TV), Good Omens - Neil Gaiman & Terry Pratchett, Harry Potter - J. K. Rowling
Genre: Alternate Universe - Good Omens Fusion, Canon-Typical Violence, Crack Crossover, Crossovers & Fandom Fusions, Fix-It of Sorts, Gen, Podfic Available, Snakes
Language: English
Status: Completed
Published: 2019-07-12
Updated: 2019-08-10
Packaged: 2020-06-26 19:50:31
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,726
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19775206
Author URL: https://archiveofourown.org/users/atamascolily/pseuds/atamascolily
Summary: Harry Potter meets a certain snake-y demon while on a trip to the zoo with the Dursleys... which mirrors another, less innocent encounter several decades earlier.





	1. Chapter 1

**Author's Note:**

  * For [burningbright](https://archiveofourown.org/users/burningbright/gifts).



"'Sssssup, kid?" hisses the giant snake in the reptile house, pressing up against the glass, its eyes unexpectedly level with Harry's. 

The label on the side of the cage says "Brazilian Boa Constrictor," but that can't possibly be right, Harry thinks, as he fights the urge to take a step backward. He doesn't know much about snakes, but he's pretty sure boas don't get this big, or have such alien amber eyes with only the faintest black slit at the center. And they certainly don't talk. He glances over his shoulder quickly, in case the Dursleys are watching, but Dudley and Piers are poking at the tuatara display while Uncle Vernon and Aunt Petunia argue with a zoo employee about the fastest way to the lion house. No one, in fact, is paying the slightest bit of attention to him at all right now--except for the snake, which is still staring at him with its unnervingly bright eyes, as if expecting a reply. 

Slowly, hesitantly, aware that this is crazy, and yet exhilirated by the sudden rush of adrenaline, he brings his face close and whispers, "Fine, thank you. How are you?" 

"Sssss, oh, fine, you know," the snake says with a shrug. How a snake can shrug when it doesn't have shoulders is a mystery but the snake makes it look easy, as if it had invented the gesture and humans had only copied it. "Nice and quiet here. A good place to relax when I need some downtime. Food's good, and plenty of it, no one asking obnoxious questions or anything. Peace and quiet are rare in my business, I'll tell you that." 

"Excuse me?" Harry says, wondering if he's heard correctly or whether Uncle Vernon is right and he really is crazy after all. Aside from a slight sibilance, though, and the faintest trace of an accent he can't quite place, the snake is perfectly intelligible. "Er--what sort of business does a boa constrictor have? --If you don't mind me asking," he adds quickly, not wanting to be rude. 

A long, slow wink. "You'd be surprised at how much I get around, kid." 

"Right," Harry says. "I suppose you did, coming from Brazil and all. I guess this place must seem like paradise compared to the wild, eh?" 

He's not sure he agrees with that--freedom seems like a better deal, all in all--but he doesn't know what else to say. He certainly doesn't want to offend the creature. 

The snake--chuckles? Yes. Definitely a chuckle there. "I've spent a lot of time in Paradise." Harry can hear the capital letter without knowing how he knows it. "Overrated, if you ask me. It's much better here, trust me. You lot don't know how good you have it, honestly."

"My lot?" Harry sneaks a glance over for the Dursleys and Piers, but all four of them are occupied by the feeding frenzy in the crocodile exhibit further down the hall, still oblivious to Harry's conversation. "My lot's not so great, actually." 

He doesn't know why he says that. The Dursleys don't like it when he talks about them, not that anyone ever listens. But something about the snake--its attitude, maybe, or the casual way in which it cocks its head as Harry speaks--makes him open up in a way he would never do with anyone else. It's not like a caged boa constrictor can actually do anything to help him. But to rebel against the Dursleys in this small way, even if it's only in his imagination, is the only kind of victory he's ever had, and he'll take it. 

"Oh?" The boa is amused. "Right. Those snobs over there, huh?" 

Harry follows the snake's gaze back to the Dursleys, who have abandoned the crocodile exhibit and are barrelling towards him at full speed. He jumps back from the glass with an involuntary start as Dudley sweeps forward, Piers at his heels, both of them banging on the glass and shouting with enthusiasm for the snake to "do something". 

The snake rolls its eyes. "So much for my nap. Break time over, I guess." 

This is a mistake. Harry knows Dudley is making a mistake as something hot and acid curls in his stomach, but it's too late to cry out in warning, even assuming Dudley would listen. The smell of sulfur hits him, and he wobbles as the ground shudders underneath him. He reaches out to the glass wall to steady himself--but collapses instead as his hand passes through empty air.

The glass is gone. Dudley and Piers are on the floor now too, screaming in terror, as the huge constrictor sidles towards them with remarkable speed for such a huge creature. With a elegant flick, the constrictor sidles neatly around the squalling pair, flicking its tongue in and out with what Harry can only describe as satisfaction. "Well, back to work, I guess. Nice meeting you, kid. See you around." 

And then it winds around the corner and is gone. 

Strange things are always happening to Harry Potter, but this is the strangest yet. In a few weeks, he will learn he is a wizard, possessing powers beyond his wildest dreams; in a few years, he will learn he is a Parselmouth, gifted with the rare and feared ability to talk to snakes. But it isn't until thirty-year-old Harry stumbles into an odd, clearly magical little bookshop tucked away in the more fashionable end of Soho that he discovers what in the world the boa constrictor was talking about. 

That particular snake is, in fact, the _last_ thing he expects to see curled up in an aged and battered leather armchair with a heat lamp trained on it from a rickety table nearby. 

" _You_ \--" Harry says, unable to summon anything more coherent.

It stirs at the sound. One glowing amber eye blinks open, focuses directly on him. 

"'Sssup, kid?" the snake says sleepily. "Small world, isn't it? Fancy meeting you here again..."


	2. Chapter 2

Nagini is cruising the city of London looking for souls to snare when she feels a tug in the direction of the... zoo? That can't be right. But there's no mistaking the pocket of darkness, that delicious flicker of spite and malice that can only mark a powerful mortal venturing into spiritually dangerous territory. The _zoo_ , of all places, though...that's a new one.

Nagini doesn't like zoos. She doesn't like much of anything on this plane of existence, really, except maybe the clothes. Crowley is right about that one--he always looks fabulous whenever he saunters in late during their staff meetings. Nagini hates to admit it, but she's a little jealous.

All right, maybe more than a little. But that's fine--envy is what makes a demon a demon, right? All that festering hatred and rage has to go _somewhere_ and Crowley is as good a target as any. In addition to being the best-dressed demon in hell (second-best, if she counts herself), he's also a complete ass.

So of course when she pops into existence, she's dressed to kill. Never know when you might commit a murder--not that you can really call it murder when your prey has such brief lives, but still. It's important to keep up appearances and all.

She decks herself head to toe in black, in a full-length mourning dress several decades out of fashion, but serves her purpose well enough. This incarnation boasts straight dark hair that flares around her head like a cobra hood before it cascades down to her waist in glistening strands. With pallid skin and almond-shaped eyes, she could be a porcelain doll straight out of some Orientalist's wet dream--if not for the slimy musk leaching out of her exposed skin and dripping down her knees, and the languid, predatory way she carries herself, as if she might go for their throat at any moment. Humans who glimpse her in this form turn away uneasily and avert their eyes, even if they don't know why.

But this one doesn't. She knows right away he's the one she wants, because he's dressed in fancy robes and stares her dead in the eye. "Who _are_ you?" he says.

"You can call me Nagini," she says. It's not her real name, of course, but it'll do. They all go by aliases these days--Crowley's doing again.

She studies her surrounding with interest. They're alone in a vast hall lined with enclosures of varying dimensions, in which reptiles lie under heated lamps with hooded eyes. There's a circle of blood traced on the marble floor and something raw and twitching at her feet. She steps over it without a second glance. "It's a rare wizard who calls a demon without knowing their name. Never know who might turn up that way."

He smirks at that. He's beautiful, in a human sort of way, but his handsome face is starting to twist in a subtle foreshadowing of the rot within. "And yet you answered."

"I'm curious," Nagini admits. The circle on the floor is a nice idea, but not binding. She walks over and through it, just to see his reaction, but the wizard doesn't even blink. She flicks out her tongue to taste the air. "To be honest, you're not much in need of temptation, are you?"

"No," he says with a sneer. "I have already transcended the petty boundaries of good and evil."

Nagini grins. Well, he can believe what he likes, but she knows better. She is a demon, after all. "What can I do for you, then? Fancy wealth beyond your wildest imagination?"

"I don't need you help for that."

She racks her brains, trying to remember what Mephistopheles did the last time he was in this situation. "The love of the most beautiful woman in the world?"

He flicks a dust mote off his sleeve. "Please. Don't be ridiculous."

She can sense she's losing his interest and plows ahead recklessly. "How about eternal life?" That's always a good one. Works every time. Comes with a few strings attached, but hey--better odds than otherwise, right?

 _Now_ she has his attention. He smiles thinly. "Once, I might have been tempted. But I am already a master of death."

Really? Nagini has to work hard to keep the skepticism off her face. All the clever mortals think that, right up to the point where Death shows up to do his business--and he doesn't take kindly to troublemakers. "Then what _do_ you need? Anything you want, I can grant it. All I ask for in exchange is your soul. Precious little good a soul does you. It's like the appendix. You won't even miss it."

"No."

"No?" she repeats, incredulous. Why did he summon a demon then, if he didn't want to bargain? She purses her lips. "You're wasting my time," she says, irritated now.

He chuckles, amused by her reaction, and deigns to explain. "My soul is... already split. You'll have to make do with your share. I'm not so foolish to give the entire thing to a servant of Hell."

A Horcrux. He made himself a Horcrux. Not only one, but several, by the sound of it. Nagini can't believe it. This is her lucky day. Even that asshole Crowley won't be able to top _this_ during the recounting of the Deeds of the Day!

"I desire a servant," the wizard continues. "My followers mean well, but their competence leaves much to be desired at time. I desire someone who will remain at my side and serve me loyally... and serve as as a repository for another piece of my soul to protect it against all comers." That careful smile again. "You would, I think, be a _most_ effective guardian."

Nagini can't believe the wickedness of it all. To split a man's soul into pieces... to ask a _demon_ to safeguard it for him... oh, that was a good one all right. The Powers Below were going to love this. This is the happiest day of her life.

She snaps her fingers and a contract appears--a scroll of parchment, bleeding red ink in a spidery copperplate hand appears in midair, accompanied by a gleaming quill. Nagini's a stickler for tradition, and it keeps the bureaucrats Below happy. "Sign here, and it's done."

He's not a complete fool. He scans the scroll first, insisting on edits here and there, which Nagini cheerfully obliges. Technically, Hell doesn't own his soul, he's just lending it to them for safe-keeping. Nagini bows and nods, all smiles.

The truth is that it doesn't really matter what the contract says--once she has an in, it would take a miracle for him to escape Hell's clutches. No point in quibbling over details before he signs.

Eventually, the wizard is satisfied and scrawls his name--"Lord Voldemort"--in a dramatic cursive flourish. He steps back. Because demoms have a flair for drama, the scroll and quill vanish with a pop and all the lights in the Hall of Reptiles go out at once.

For a long moment, the wizard and demon stand in the darkness, and neither says a word. They know what must come next. Nagini reaches out and manipulates reality just enough to make it happen.

There is a clatter and bang in the distance, a flashing bob of light that grows larger and larger as the night watchman comes towards, his torch flickering off the gild and gleam of the cages.

"Hallo," he calls. He is an old, fat, balding man, without a magical bone in his body, unprepared for anything out of the ordinary. He hesitates for a second, then presses forward. "Power's out, but I thought I heard something. Is anybody there--?"

Voldemort draws his wand. " _Avada kedavra_!"

There is a blinding flash of green light, and the guard crumples to the floor, sliding to a halt at the edge of the bloody circle. Even as he falls, Voldemort tugs at his temple, and mutters, and something heavy and glowing appears in his hands, as if he yanks a chunk of his own brain out of his skull.

She sniffs appreciatively. He's still beautiful, but... his skin is a shade paler, his eyes are a trifle redder, and the rot is a little more visible now on the surface. What a glorious thing to witness, the degradation and dismantling of a human soul. 

Nagini holds her hand out, and he dumps it unceremoniously into her palm. The edges are jagged and sharp, and the whole thing oozes sticky red trails of ichor. It is monstrous and disgusting, and the most beautiful thing she has ever seen.

She brings it up to her lips, as if to kiss it. Instead, she unhinges her jaw and swallows it whole.

"You'll need a new form," Voldemort says, gesturing to her body. "I'm not ready for my enemies or my followers to see me allied with so... obviously infernal being. Better to keep them guessing, don't you think?"

She nods, relaxing into the form God gave her and Crowley when they rebelled, curling in sinuous coils at his feet.

"Will this do, _Master?_ " she says in Parseltongue, the language of snakes.

Her choice pleases him, as she knew it would. She knows Tom Riddle intimately now, knows him better than he knows himself. How could she not? The soul-fragment throbs inside her now, fighting to get out, but it's too late.

"Excellent." The deed done, he is already too preoccupied with what comes next to pay her any mind. "I've always liked snakes. You will do nicely."

As if he had any choice now. "Yes, Master," she hisses. "What are your orders?"

He gestures contemptuously to the body on the floor. "Clean up this mess. I know how much you demons enjoy eating, and I assure you, there will be plenty of opportunities as long as you remain by my side."

It's more fun when they're alive and screaming, but Nagini is all too happy to oblige. A Horcrux, a murder, and a meal, all in one day, and with plenty of mayhem to come--oh, this is going to be good. The Powers Below will be so please.

Crowly is going to be so pissed when she shows him up at their next meeting.

**Author's Note:**

> Yeah, okay, so Harry ought to have lost his Parselmouth ability when he ditched the piece of Voldemort's soul inhabiting his body, but Crowley is a demon, so I'm sure he's able to make himself understood even in snake form.

**Works inspired by this one:**

  * [[podfic] In the Reptile House](https://archiveofourown.org/works/21624655) by [lilypods (atamascolily)](https://archiveofourown.org/users/atamascolily/pseuds/lilypods)




End file.
